﻿//===================================================================================
// Microsoft patterns & practices
// Composite Application Guidance for Windows Presentation Foundation and Silverlight
//===================================================================================
// Copyright (c) Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===================================================================================
// The example companies, organizations, products, domain names,
// e-mail addresses, logos, people, places, and events depicted
// herein are fictitious.  No association with any real company,
// organization, product, domain name, email address, logo, person,
// places, or events is intended or should be inferred.
//===================================================================================
using System;
using Carcass.Events;

namespace Carcass.Presentation.Events
{
  ///<summary>
  /// Extends <see cref="EventSubscription{TPayload}"/> to invoke the <see cref="EventSubscription{TPayload}.Action"/> delegate
  /// in a specific <see cref="Dispatcher"/>.
  ///</summary>
  /// <typeparam name="TPayload">The type to use for the generic <see cref="System.Action{TPayload}"/> and <see cref="Predicate{TPayload}"/> types.</typeparam>
  public class DispatcherEventSubscription<TPayload> : EventSubscription<TPayload>
  {
    private readonly IDispatcherFacade dispatcher;

    ///<summary>
    /// Creates a new instance of <see cref="BackgroundEventSubscription{TPayload}"/>.
    ///</summary>
    ///<param name="actionReference">A reference to a delegate of type <see cref="System.Action{TPayload}"/>.</param>
    ///<param name="filterReference">A reference to a delegate of type <see cref="Predicate{TPayload}"/>.</param>
    ///<param name="dispatcher">The dispatcher to use when executing the <paramref name="actionReference"/> delegate.</param>
    ///<exception cref="ArgumentNullException">When <paramref name="actionReference"/> or <see paramref="filterReference"/> are <see langword="null" />.</exception>
    ///<exception cref="ArgumentException">When the target of <paramref name="actionReference"/> is not of type <see cref="System.Action{TPayload}"/>,
    ///or the target of <paramref name="filterReference"/> is not of type <see cref="Predicate{TPayload}"/>.</exception>
    public DispatcherEventSubscription(IDelegateReference actionReference, IDelegateReference filterReference, IDispatcherFacade dispatcher)
      : base(actionReference, filterReference)
    {
      this.dispatcher = dispatcher;
    }

    /// <summary>
    /// Invokes the specified <see cref="System.Action{TPayload}"/> asynchronously in the specified <see cref="Dispatcher"/>.
    /// </summary>
    /// <param name="action">The action to execute.</param>
    /// <param name="argument">The payload to pass <paramref name="action"/> while invoking it.</param>
    public override void InvokeAction(Action<TPayload> action, TPayload argument)
    {
      dispatcher.BeginInvoke(action, argument);
    }
  }
}
